There are problems associated with filling the toothpaste package effectively and reliably if the toothpaste exhibits the stringy effect and tailing, particularly for toothpaste formulations containing a significant proportion of calcium carbonate particles.
Specifically, traditional manufacturing processes result in toothpastes having a granular texture which is not satisfactory because consumers require toothpaste compositions which are smooth in texture.
There is accordingly a need in the art for a method of manufacturing a toothpaste composition which contains calcium carbonate particles and exhibits good rheological properties, in particular reduced stringiness and reduced tailing, and has a smooth texture.
In addition, it is well known to manufacture striped toothpastes, in which a first toothpaste phase is provided with stripes of a second phase, of toothpaste or gel, when the toothpaste is extruded as a strip from a tube or other packaging. The first toothpaste phase is typically white and the second phase is typically colored. It is an important aesthetic requirement for the consumer that the differently colored phases have a sharp boundary between them and that the different colorants do not appear to bleed from one phase into the adjacent phase.
The binder component in the toothpaste has a significant impact on the stripe quality of the extruded strip to form a stable extrudable paste including the abrasive particles and the liquid phase. In striped toothpaste formulations containing a significant proportion of calcium carbonate particles, it is known to use a binder system which controls the stripe quality. In particular, it is known to use a binder system incorporating the combination of carboxymethyl cellulose (CMC) and magnesium aluminium silicate (MAS) to provide a high stripe quality. However, the use of magnesium aluminium silicate (MAS) suffers from the problem that currently there are only a few qualified suppliers of toothpaste-grade magnesium aluminium silicate (MAS), which increases the cost and complexity of the supply chain.
There is accordingly a need in the art for a method of manufacturing a striped toothpaste composition which exhibits high stripe quality but avoids the supply chain problems of the known binder system incorporating the combination of carboxymethyl cellulose (CMC) and magnesium aluminium silicate (MAS).